Abuse of alcohol and drugs can negatively impact cognitive growth of the teenage brain during a critical time of development. Teens who abuse these substances are more likely to engage in risky sexual activity, drive under the influence, abuse multiple substances and commit crimes. Abuse of alcohol and drugs is also linked to physical and mental health problems, poor academic performance and disengagement from peers, family, schools and community. The negative consequences of teen alcohol and drug abuse can carry over into adulthood. Overall, alcohol and drug use by adolescents have declined during the past decade, although patterns vary by substance.